CURSE you, EINSTEIN! Humanity still chained in relativistic PRISON

Re: Gravity Propagation Question

c

if our Sun exploded the moment you read this. It will take ~8 minutes for the gravitational change to reach us.

Re: Gravity Propagation Question

The speed of gravity is apparently finite... I believe that's been known for some time. Newton thought it was infinite, but apparently observations of Mercury's orbit in the mid-1800s showed that the planet's behaviour could not be explained by purely Newtonian physics.

Modern work on the actual speed of gravity is pretty arcane. Current theories suggest that it isn't any faster than the speed of light, but the related papers are well beyond my ability to understand. Good luck ;-)

(also, "The force you impart to the rod propagates through the entire rod much faster than light speed"... really? if that were true, we wouldn't be arguing about the existence of superluminal physics still!)

Re: Gravity Propagation Question

[blush] Kindly substitute "force" for "light" in the foregoing post.

Re: Us2them

probably for the best.....

Re: Us2them

First, while Man is obviously dangerous to Man, it is the height of hubris to think the Universe is losing sleep over our popguns and petty bickering. Second, Man is no more violent than, say, bacteria. Or my cats, which fight constantly, for no apparent reason. Third, eternity is a very long time, and there is a great deal we still do not know.

Re: Quantum, eh?

As far as I can see, the findings presented in the article simply show an unrelated confirmation of Relativity, rather than a specific refutation of the possibility of Collapsar travel. Moreover, there remains a great deal we do not understand - such as why 95% of the Universe remains unaccounted-for, or why Relativity and Quantum Mechanics can't be reconciled. For starters. Milk and sugar in mine, thanks.

Re: Since this is ask-a-stoopid-question-Friday

The pressure is still greatest at the core. That 's why the middle part of the sun is where all the burning happens.

Re: Since this is ask-a-stoopid-question-Friday

"The black hole will actually form at some point on the _surface_ of the neutron-star, right?"

I would imagine that's right, as long as you substitute "event horizon" for "black hole".

Nearest star is 4 Ly away, travelling at accelerations humans can stand, years is definitely the minimum. Leaving aside the energy costs, it'd take nearly a year to hit C, so you'd have travelled about .5 LY in the first year.

Lorentz dilation doesn't take it down much in the velocity changing phase given that for a long chunk of speeding up and slowing down you'd be experiencing only minor dilation.

Of course at lightspeed (if such a thing were possible) you wouldn't experience time, but the two subjective years of speeding up and slowing down would be longer than a year my back of the envelope maths tells me.

Of course the bonus about accelerating to lightspeed and then travelling at it is that all journeys would,subjectively, take exactly the same time.

In reality of course the energy requirements get sufficiently onerous as you get faster that constant acceleration is a non-starter.

Re: Anything is still possible

Feel free to adopt that motto if it makes you happy, but it's no consequentially different from simple subjective solipsism - believing that nothing outside the conscious self can be known. Of course in that case anything is always possible; all of your perceptions could be hallucinations.

But there's little point in taking solipsism as a substantive foundation - of trying to act based on it. And there's equally little point in trying to act on the belief that physics is different in parts of the universe we can perceive. Maybe so, but so what?

Formal and empirical results that challenge our models are interesting, because they suggest there's something new to know, and perhaps to do. Theories that challenge our models are sometimes interesting, because investigating them might lead to new formal or empirical results. Saying "maybe our models don't hold under some conditions that we have no empirical access to, and no formal mechanisms to describe" is chit-chat.

Re: Einstein's Limit and Time Travel

You cant measure anything faster than your measuring stick.